package com.atguigu.gulimall.product.service.impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {

        //1 查出所有分类
        List<CategoryEntity> list = baseMapper.selectList(null);
        //2 组装成父子的树形结构

        return list.stream()
                .filter(item -> item.getParentCid() == 0)
                .peek(item -> item.setChildren(getChildren(item, list)))
                .sorted(Comparator.comparingInt(i -> (i.getSort() == null ? 0 : i.getSort())))
                .collect(Collectors.toList());
    }


    private List<CategoryEntity> getChildren(CategoryEntity category, List<CategoryEntity> list) {

        return list.stream().filter(item -> item.getParentCid().equals(category.getCatId()))
                .map(item -> {

                    item.setChildren(getChildren(item, list));

                    return item;
                }).sorted(Comparator.comparingInt(i -> (i.getSort() == null ? 0 : i.getSort()))).collect(Collectors.toList());
    }
}